Suicide rates among cancer patients were determined from the Connectict SEER Cancer Registry and compared with age-matched Connecticut State suicide rates to estimate relative risks. Among male cancer patients a two-fold risk was found, but no excess risk for females. For men, a larger risk appeared the first few years after diagnosis than later. Preliminary data, only partially controlled for other variables, suggest slightly higher risk for ever married than never married, and clearly higher risk among patients with metastasized than in those with localized tumors. Slightly greater risk appears in surgical patients than in those treated otherwise.